Collator technology has improved steadily. Demand has arisen for fast collating with expanded capabilities. With this demand has also come correlative problems in the collator mechanics. The art of microprocessor control has allowed many of these problems to be reduced or eliminated. This invention relates to use of a sophisticated logic control means which will allow the collator to perform tasks more quickly with fewer problems. The collator functions as a slave to a sophisticated, computer-controlled photocopier. Through a computer link, the two devices can operate together to better achieve desired results.
There are far too many collator patents to describe them all in this introductory section. However, a few should be mentioned. U.S. Pat. No. 3,905,594 (Davis) discloses a randomly programmed, sequential sheetsorting machine for filling trays with differing numbers of sheets. A computer memory stores input on the number of sheets desired in a particular tray. When operating, the collator counts the sheets for each tray. Each job must be individually programmed. Because most collating jobs require sorting a consistent number of sheets to each tray, the program capability, which is the essence of the Davis invention, has limited use.
U.S. Pat. No. 3,772,970 (Snellman et al.) discloses another collator which may be programmed to distribute selected numbers of sheets to selected sheet receivers. This collator uses relays and contacts to perform its desired sorting. This electromechanical control system requires manual programming before each sorting job.
Yet another collator for placing an unequal number of sheets into separate trays is disclosed in U.S. Pat. No. 3,572,685 (Snellman). A dispatcher assembly controls the operation of a distributor in accordance with sequentially recorded information advanced through an information-sensing or "readout" section of the assembly. Magnetic tape at each tray is read to determine how many sheets should be placed in that tray. Alternatively, a punch card reader may be used. A memory stores the information on sheets and trays and controls the sheet deflector assembly.
U.S. Pat. No. 3,618,936 (Ziehm) discloses an improved jam detection system for sorting apparatus. The system comprises program means to actuate individual deflector members to route documents into a selected tray in a predetermined sequence, sensing means disposed along the feed path for the document, and a timing circuit with an output to control the feed path.
U.S. Pat. No. 3,709,485 (Acquaviva, Jr.) discloses a control circuit for a sorting system. A jam detection circuit times signals received. The circuit is coupled to the motor drive of the conveyor. When sheets jam, the conveyor will be shut down. Relays and phototransistors along the conveyor collect information. Comparison circuits count the numbers of sheets reaching trays.
Although some of these patents disclose limited aspects of microprocessor control, none discloses the intercommunication and cooperation with a sophisticated, computer-controlled photocopier. Much of the utility of this invention relates to its flexibility in responding to tasks ordered by the photocopier. Its ability to store functions for later use, to detect errors, and to converse with its overlord photocopier makes this invention a valuable and much desired improvement over other machines.